The present invention relates to image presentation and, more particularly, to devices, processes and products involving photographic images that are adapted for both direct observation and optical projection. Conventionally, a photographic presentation that is intended for direct observation is associated with a diffuse reflecting distribution, by which imaging light is returned to an observer's eyes. Conventionally, a photographic presentation that is intended for optical projection is associated with a transparent support, by which condensed light is directed through the photographic image toward a viewing screen. Under various circumstances, it is desired that a single presentation permit both direct observation and optical projection.
The primary object of the present invention is the provision of photographic devices, processes and products involving a photographic image stratum for visual display and a liquid crystal stratum having a diffuse reflective phase by which the image may be observed directly and a clear transparent phase by which the image may be projected. Generally, diffusely reflecting materials provide a myriad of refracting discontinuities, which, in one form, are defined by the surfaces of minute transparent crystal domains that scatter incident rays of light at random by both external and internal reflection. On the other hand, transparent materials are amorphic in the sense that they have no such refracting discontinuities with respect to visible light. Liquid crystal materials can exhibit either a presence or an absence of refracting discontinuities depending on energy level. The contemplated combination of photographic image and liquid crystal, in one form, is mounted on a clear base that permits diascopic projection. In another form, the combination is mounted on a metallic reflecting base, which is obscured by the liquid crystal when the image is observed directly but which serves as a specular backing for episcopic projection when the liquid crystal is clear.
Other objects of the present invention will in part be obvious and will in part appear hereinafter.
The invention accordingly comprises the devices, processes and products having the components, steps and interrleationships which are presented in the accompanying disclosure, the scope of which will be indicated in the appended claims.